<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../vue-2.5.21/dist/vue.js"></script>
</head>
<body>
  <div id="app">
    <input type="text"  :value="message" v-on:input="valueChange">
    {{message}}
  </div>
</body>
<script>
  const app = new Vue({
    el:"#app",
    data: {
      message: "nihao",
    },
    methods: {
      valueChange(){
        console.log('----');
      }
    }
  })
</script>
</html>